January 31, 2002

Good morning, this is Ron Johnson with your Gallatin National Forest
Avalanche Advisory issued on Thursday, January 31st, at 7:30 am.  A
Recreation Trails Grant administered by the Montana Department of Fish,
Wildlife and Parks sponsor today's advisory.  This advisory does not apply
to operating ski areas.

                CURRENT CONDITIONS AND WEATHER DISCUSSION:

During the past 24 hours, 3 to 6 inches of low density snow fell in the
Bridger and Northern Gallatin Ranges, while an inch or two of the fluffy
stuff only dusted the rest of our area.    Today, a northwest flow aloft
has enough moisture that another 1 to 3 inches of snow is expected by
tomorrow morning.  Ridgetop winds have been and will continue to blow from
the west at about 20 mph.  Mountain temperatures are slowly warming and by
this afternoon, they should reach the teens F.

                    SNOWPACK AND AVALANCHE DISCUSSION:

The Bridger Range, and Northern Gallatin and Northern Madison Ranges:

The wind will be strong enough to blow the few inches of snow that fell in
the northern mountains onto the lee side of ridges and gullies.  The wind
deposited snow will be on top of lower density snow and the resulting wind
slabs could be sensitive enough to break and slide on steeper slopes.  
The smooth pillows of wind slab should be about 6 to 12 inches deep.  You
should take some time and poke around on a low angled, lee slope.  Dig 
down though the slab and see if it is sitting on low density, less cohesive
snow.  If it is, be sure to take that observation into account before you
jump on to a steeper wind loaded slope.  For today, for the northern
mountains, I consider the avalanche danger to be MODERATE on recently wind
loaded slopes steeper than 35 degrees.  The avalanche danger on other
slopes should be LOW.

The Southern Gallatin, Southern Madison and Washburn Ranges, the Lionhead
area, and the mountains around Cooke City:

It has been several days since the any significant snow has been added 
to the snowpack in the southern mountains.  The exception is on wind loaded
slopes where some isolated wind slabs continue to respond to explosives
used by the ski patrol at Big Sky.  Generally the avalanche danger has
decreased from last weekend, when avalanches and obvious signs of snowpack
instability were observed in the mountains around Cooke City and in the
Southern Madison Range.  A layer of buried surface hoar persists in the
mountains around West Yellowstone.  Last weekend, this layer produced some
collapsing and cracking of the snowpack.  Around Cooke City, on southerly
facing slopes, faceted snow on an ice crust was the weak layer responsible
for some avalanche activity on Saturday and Sunday.  Once again, I believe
that without any significant stress being added to the snowpack during the
past few days, these layers are less likely to pose problems.  Still, they
warrant attention as do wind loaded slopes and, for today, on all slopes
steeper than 35 degrees I consider the avalanche danger in the southern
mountains to be MODERATE.

                           JUST A FEW THOUGHTS:

The lure of playing in deep snow on steep slopes is very powerful and it is
possible to misjudge the stability of the snow on a given slope.  This 
combination means that folks will be caught in avalanches.   While it is
possible to make a misjudgment about the snow it is also possible to make
decisions that reduce the risk of being caught in an avalanche.  Most of
the recent avalanches have involved more than one person.  Please, consider
only exposing one person at a time to the avalanche danger when playing on
steep, snow covered slopes.  End of sermon!

The next advisory will be issued tomorrow morning at 7:30 am.

END